First cook questions with HeaterMeter 4.3 and Rotodamper 3

[Nick T Wellman]

Hey everyone, I had my first successful smoke with my Heatermeter and RD3 running on my Char-Griller Smokin Pro with with the offset smoker box on the right. Thanks to Ralph Trimble, I received the parts for my Rotodamper on Saturday, and by Sunday morning everything was assembled and ready to smoke a rack of ribs. As I said the cook was successful...in that I had smoked ribs at the end, however, I wouldn't say that everything went smoothly. I know that I need to seal up my smoker better so that the HM can more accurately regulate the air flow, but I mistakenly thought it would go a bit better. I made a quick video that shows the set-up, so I think it will help my questions make more sense. https://youtu.be/9eTXDAixoz0

Here are my questions:

1. Do you all find that using wood "logs", about 4" in diameter and 12 inches long works better than the so called "chunks" in a situation like this. I chose to use a combination of chunks and charcoal briquettes to attempt to maintain my heat, and I found that the HM couldn't regulate that combination for long, without some intervention on my part. I have seen lots of guys post their results with a long steady temp without much fiddling on their part, and eventually I want to be able to achieve the same.

2. As you can see in the video, my RD is attached to the offset smoker box with the cat bowl method that many others have used. With the small 50mm fan, I felt like it wasn't powerful enough to push air across to the flames, but that may just be in my head. I was thinking about modifying the set-up so that the air hits the coals more directly by drilling a hole in the back/bottom of my offset smoker box and running the 1"pipe in near where the coals sit. I have even considered splitting off the 1" pipe into two smaller 1/2" inch pipes with small holes drilled in them and running those pipes closer to where the coals sit. Thoughs?

3. I know that PID settings can affect the operation greatly, and that there are many variables that can affect where you set your PID settings. I have researched this topic a bit and think I understand better, but I am wondering if anyone out there is using a smoker like mine and would be willing to share their PID values. I know I can dial things in using the log files, but for now since I only have one cook under my belt, I was hoping someone out there had something similar that I could check out.

Thanks for reading this post, and thanks in advance for any advice you can offer. I have to say that even though I am new to PID and smoking in general, I feel like I know so much already because I have been scouring these forums for help. It is places like this and helpful folks like this community that have answered so many questions for me in the past, and I hope to be giving answers to questions like this soon enough.

Nick

 

[Andrew F]

What exactly is the problem you are having? You say it isn't regulating the heat well, are the temps dropping or rising or both. I'd guess dropping judging by the size of your fire.

1. Charcoal and chunks are fine, but you should use a charcoal basket to be able to load more fuel in there for longer smokes.

2. Adding pipe and bends will restrict the flow of air. Not much, but you already think you have a low air problem.

3. Sorry, can't help there.


IF I understand the logic correctly, the RD set-up is for very efficient smokers that need fine control to maintain temp. Your Char-Griller is not such a beast. You may need a bigger blower.

 

[John Bostwick]

That's a pretty big smoker for a small blower. You may have issues holding temps. If your blower is on at 100% and the temperature is not moving up then your blower is to small. I would have tried an rd25. My UDS has issues with a stock blower. An UDS is 55 gallons drum. Your fire box and smoking chamber probably more then that combined.

 

[SteveCK]

Someone on this forum is using a MicroDamper with that exact pit, I can't for the life of me remember who that is and I'm not finding it when I'm searching through my emails so hopefully he sees this and can try to help you out.

 

[Nick T Wellman]

Thanks for your responses. I would like to believe that a HeaterMeter can be used on even a smoker the size of the one that I have and be used effectively. I really feel like it makes a big difference how well the grill is sealed from outside air, because if it is well sealed, then not only can high temperatures be achieved by holding in the heat, but the fire and temps can be more effectively controlled by the damper/blower. That being said, I am new to this, so if you are saying I am doing it wrong, and can prove that, then I will look at other methods. @SteveCK, if you can think of that name, I would love to check out any posts they have to compare notes.

Nick

 

[John Bostwick]

Both bbqguru.com and stoker both say to get either a large blower or a 10cfm blower. An UDS needs atleast a 8.7cfm and it looks like the Char-Griller Smokin Pro is a tad bigger then a UDS. I have tried smaller blowers in the past 5 years, and they work ok in warmer weather, but forget it in anything colder then 70°. There is just not enough insulation on a Char-Griller Smokin Pro, same as a UDS, to keep in the heat.

 

[Andrew F]

I think you might be over thinking it a bit. Sealing your grill will not help hold higher temps. You loose more heat from the metal then you do from leaks. Sealing a smoker helps in achieving a consistent temperature because there is no "uncontrolled" air reaching the fire, keeping it from "running away."

Sure, I suppose that some cold air might be able to blow into the cooking chamber, but it would have to be a pretty strong wind.

Are you having trouble maintaining set temperature, as in you can reach 225, but then it starts to drop and you have to add more fuel, or does it shoot to 350, then drops to 180, then back up to 400....?
Does your fan ever turn off?
Does the damper even think of closing?

 

[Ruben P]

I have a similiar smoker/HM setup, I solved my temperaure problems by:
1. Sealing the fire box.
2. Placing a piece of 1" copper pipe that extended from the blower into the firebox onto the fire.

 

[Nick T Wellman]

John, Andrew and Ruben thanks for your replies. I'm not ready to give up on this build yet and here is why. I have done a bunch of research on this smoker, and with some mods there are guys who are plenty happy using this as their daily smoker. I know that I have some air leak on the smoker box and the main compartment that I can seal up. The smoker box can be used as a tabletop grill as well and since I didn't put the legs on, there are some open holes where I forgot to put the screws in to seal off air flow. There is also a gap around the main door of the smoker box and around the edge of the ashdrawer where it meets the body of the box.

During the first cook I had some times where it would reach my set temp, the HM would stop the fan and close the damper but the heat would continue to rise. Once it continued to climb from 250 up above 300 when I wasn't able to watch or tend to it. This leads me to believe that there is still enough air getting in the fire box that the fire could continue to grow. There were other times when the HM output was full, but I couldn't get the temp back up without adding fuel. I think for my first cook, I just didn't have a big enough fire to start with.

Aside from sealing the grill, I'm also planning to add a couple more things. I am going to make a Tuning plate because I think the heat could be better distributed from right to left, and I am going to line the bottom with 1" brick or lavarock to help retain heat better. I think I'll also extend the exhaust pipe down to around grate level so that heat doesn't automatically go up and out. I'll hold off on any further RD3 additions until after my next cook, but that is what I have in mind for now.

 

[SteveCK]

A few things to keep in mind. These pits weren't designed for set and forgot action, they were made for adding fuel every ~45min. Because of the way they run they also don't need to be completely airtight, though it helps a little. If you plan on running your pit "set and forget" you should seriously think about building a charcoal basket. Also keep in mind that any bricks/lavarocks you might add to increase thermal mass means you have to heat them up first before they provide any service, which means you'll have to start with a large fire and come back down to smaller one to equalize your fire with what your bricks are putting out. And lastly, these are not efficient cookers so as long as you are running your pit with a 10-15* +/- temp swing consider it a successful cook.

 

[Nick T Wellman]

For anyone interested I have some updates regarding my modified Chargriller COS/HeaterMeter/RotoDamper build. I am at a point now after some more mods, a change to the blower, a bunch more tinkering that I am happy with the performance of this smoker! Since I last posted, I have done several more cooks, modifying a thing or two before each cook to see if I could improve performance. Here is what finally made the biggest difference.

I purchased an inexpensive generic 26 cfm blower from amazon to replace the 6 cfm blower that comes in the hardware kit from HeaterMeter.com. I had to mount it in a PVC junction box that I bought at Lowes becuase the new one wouldn't fit in the 3D printed RD3 case that I bought. I then modified the lid of the PVC box to accept the RotoDamper, and adapted the box to accept the 1" pipe that I already had. This, combined with sealing the fire box, has allowed the HeaterMeter to regulate the temperature accurately within a degree of my set point for approximately two hours or until I have to add more fuel. I am thrilled with how it has all turned out, and would like to thank anyone and everyone here who provided tips, advice or critiques, as they all led me to this answer in some way. If you are working with a COS like I did, it is possible to achieve success, you just have to be willing to work with what you have and realize that it will take more to make a less efficient smoker work for you. I haven't done a follow up video yet, but attached is a picture of the modified blower/damper.